As a creator and architect of Batman’s world, Bill Finger had a crucial impact on the Dark Knight. Finger was working as a shoe salesman when he met Bob Kane at a party. The aspiring writer joined Bob Kane’s studio and became a ghostwriter on the comic strips Rusty and Clip Carson.

After Superman became a hit in 1938, many comic professionals began brainstorming new superheroes. Kane was working on his own superhero ideas and showed Finger some early sketches of Batman. Finger suggested tweaks to the design, which would cement the character’s iconic look, including giving him a cowl and cape instead of a domino mask and wings, adding gloves, and removing red from the costume.

In addition to these distinctive changes to Batman, Finger devised the name Bruce Wayne and developed the superhero into a detective. He wrote Batman’s debut in Detective Comics #27 (May 1939), as well as many early Batman stories, with Kane providing the art.

The following year, Finger co-created Robin with Kane and artist Jerry Robinson. He and Kane discussed the need for a sidekick and since Finger likened Batman to a Sherlock Holmes-type character, Robin would be his Watson. The Boy Wonder debuted in Detective Comics #38 (April 1940).

At the same time, Finger wrote the first issue of Batman (spring 1940), which introduced two Batman mainstays – Joker and Catwoman. For the Joker (a co-creation between Finger, Kane, and Robinson), Finger recalled The Man Who Laughs novel by Victor Hugo with a character bearing a permanent grin as a result of an operation. Finger and Kane created Catwoman together as a way to pull in female readers and add a bit of romantic appeal to the book.

The team of Finger and Kane would go on to co-create several more important Batman villains in the early ’40s. They added Penguin in Detective Comics #58 (December 1941), who Finger envisioned as a caricature of the stuffy, upper class, likening them to emperor penguins. They co-created Two-Face in Detective Comics (August 1942), developing a Jekyll and Hyde persona based in tragedy. The pair also collaborated on Clayface and Scarecrow in ’40 and ’41, respectively.

Finger added more important characters to Batman’s world, including co-creating Riddler with Dick Sprang in Detective Comics #140 (October 1948). He and Sheldon Moldoff partnered on creating Calendar Man, the villain who commits crimes that line up with holidays, for Detective Comics #259 (September 1958). Finger and Moldoff also created Betty Kane, the original Bat-Girl in Batman #139 (April 1961).

In addition to the roster of characters, Finger co-created the Batmobile and Batcave, is credited with naming Gotham City, and wrote the stories that introduced the full-size Tyrannosaurus Rex and giant Lincoln penny in the Batcave. He also joined Kane on the Batman comic strip in the mid-1940s.

Outside of Batman comics, Finger aided in the creation of Green Lantern with Martin Nodell and co-created Wildcat with Irwin Hasen. He also wrote for films and television shows, including the Batman season two episodes “The Clock King’s Crazy Crimes” and “The Clock King Gets Crowned.”

Finger was inducted into the Jack Kirby Hall of Fame in 1994, the Will Eisner Comic Book Hall of Fame in 1999, and the Overstreet Hall of Fame in 2013. In celebration of his work, Comic-Con International established the Bill Finger Award for Excellence in Comic Book Writing in 2005.